1. Technical Field
This invention relates generally to static gaskets of the type used to establish a gas/fluid-tight seal between two members to be clamped together, and more particularly to multilayer static gaskets having a function layer with a seal bead and a separate stopper layer.
2. Related Art
In establishing a gas/fluid-tight seal between two members to be clamped together, such as a cylinder head and engine block or an exhaust manifold and a cylinder head, for example, it is common to use a static gasket having multiple layers. Generally, at least one of the layers of the multilayer gasket, sometimes referred to as a functional layer, has a seal bead to facilitate establishing a gas/fluid-tight seal. Another of the layers, sometimes referred to as a distance layer or stopper layer, is configured to abut the functional layer in an effort to prevent the seal bead of the functional layer from becoming completely flattened. If, while fastening the members to be clamped together, the seal bead is over-compressed and substantially flattened, in addition to the seal bead losing its ability to exert a high compression sealing pressure, fatigue cracks can form in the area of the seal bead, such as during clamping or while in use. The fatigue cracks ultimately reduce the ability of the static gasket to establish an air and/or fluid-tight seal, thereby potentially diminishing the life and performance of the engine. As such, it is important that the stopper layer perform its intended function, while also being economical in manufacture.